1. Field of the Invention
This invention relates to a recording and reproducing apparatus with a high speed search function, and more particularly to improvements in its reel pedestal drive mechanism.
2. Description of the Prior Art
In magnetic recording and reproducing apparatuses with fast speed search functions, wherein tape engaging a recording-playback head is driven at high speed to reproduce images in a so-called "search", it is necessary to cope with the problem of regulating tape movement so that the tape may be wound at the high speed. The required torque transfer system for the tape supply and tape take up reel pedestals thus becomes very complex. For this reason, conventional types of such systems have utilized either separate electrically controlled motors for each reel pedestal, or complicated mechanical clutch mechanisms in order to accomplish the desired reel pedestal drive in each mode. The use of such systems therefore results in complex apparatuses which constitute one of the bottlenecks in attempts to minimize the bulk and size and weight of the system. Aside from requiring the actuating member for the ordinary fast feed and rewind, the actuation control portion also must have two actuating members adapted to operate only in the search mode for the forward and reverse feeds respectively. This increases the complexity of the actuation control portion and also calls for an increase in the space which the actuation control portion occupies. These problems become particularly serious when compactness, light weight, and good manageability are extremely important as in portable magnetic recording and reproducing apparatuses.
Generally, in the search mode, the recorder operates by rotating the capstan at a far higher speed then in the ordinary recording or reproducing mode. This causes the tape to run in the forward or reverse direction at this increased speed. The reel which takes up the tape, namely the take up reel when the tape runs in the forward direction, or the supply reel when the tape movement is reversed, must be driven through a slip-coupling of a prescribed appropriate transfer torque. The number of revolutions is adjusted to be slightly faster than the tape speed required in the search mode. On the other hand, in the ordinary rewind or fast feed mode, the supply reel or take up reel is coupled directly to the output of the motor. Since, in this case, the winding torque increases and the tape runs at a high speed, it is undesirable to permit the tape to remain in contact with the tape guide drum and other members such as the stationary head during that operation.